Jan Sefcik

Research Interests

Our research deals with materials and processes at colloidal (nanometer to micrometer) length scales. The focus is on synthesis and processing of particulate, colloidal and biomolecular systems.

Particle formation processes/pharmaceutical engineering

Numerous pharmaceutical particulates are formed through antisolvent driven processes, where two solutions are mixed in order to create a thermodynamic driving force for particle formation due to a limited solubility of one or more solutes in the resulting solvent mixture. Such processes are often mixing controlled and can lead to a wide range of intermediate and/or metastable liquid or solid phases. We study kinetics and mechanisms of these processes in order to design and novel continuous processes for manufacturing of nanostructured particles for various pharmaceutical applications. We also study subsequent downstream processes and their effects on resulting particulate products.

Protein Aggregation

Understanding, controlling and utilizing colloidal interactions of proteins is crucial for their downstream processing, including purification, sterilization and storage. Protein interactions with each other determine whether they stay stable in solution or whether they aggregate. Understanding and tuning of protein interactions is thus necessary for improvement of the lifetime stability of therapeutic proteins as well as for rational development of novel separation and sensing procedures for bioprocessing. In fact, there are numerous issues in biotechnology and biomedical engineering, where protein aggregation phenomena have been identified as key factors controlling our success in producing, sensing, handling, and applying biomaterials and therapeutics as desired. We study protein aggregation in solutions under non-equilibrium conditions. The proteins of interest include enzymes and therapeutic proteins in applications such as heat treatment or bioseparations. The modelling work is focused in detailed scattering and spectroscopic characterisation of aggregating protein systems as well as on development and validation of population balance models describing how the mass distribution, structure and activity of protein aggregates evolve in time.